Georg
Simon Ohm

Although he discovered one of
the most fundamental laws of current electricity, he was virtually
ignored for most of his life by scientists in his own country.

In 1827 Georg Simon Ohm discovered some laws relating to the
strength of a current in a wire. Ohm found that electricity acts
like water in a pipe.

Ohm discovered that the current
in a circuit is directly proportional to the electric pressure
and inversely to the resistance of the conductors.

Ohm's Law is one of the most important things that you will use
throughout your electrical career. It is a mathematical tool which is of the greatest use in determining
an unknown factor of voltage, current or resistance in an electrical
circuit in which the other two factors are unknown.

It is a simple law that states the relationship between voltage,
current and resistance in a mathematical equation. In electrical
terms, voltage is represented by the letter "E"
(electromotive force) Current by the letter "I"
(intensity), and resistance by the letter "R".

The Ohm's formula cannot work properly unless all values are
expressed in the correct units of measurement:

VOLTAGE is expressed in VOLTS
CURRENT is expressed in AMPERES
RESISTANCE is expressed in OHMS